Variable capacity pump



Jan. l5, 1935. F, PQZIERDEN 1,988,407

VARIABLE CAPACITY PUMP Filed oct. 12, 1952 5 sheets-sheet r 1 'ffzmlw Jan. 15,1935. A l F. P. ZIERDEN 1,988,407

VARIABLE CAPACITY PUMP l Filed Oct. l2, 1932 5 Sheets-Sheec,y 2

Jan. 15, 1935;

F. P. zlE'RDEN 1,988,407

VARIABLE CAPACI TY PUMP Filed 0ct. l2, 1952` 5 Shees-Sheet 5 l @wm/Wto@ it f. ziefaan.

Jan. l5, 1935.

F'. P. ZIERDEN VARIABLE CAPACITY PUMP Filed Oct. 12, 1932 5 SheetS-Sheet 4 F. P. ZIERDEN VARIABLE 4CAPACITY PUMP Jan. 1 5, 1935.

Filed oct. 12; 1932 5 Sheeics-Shel 5 f. f7. Zzerden.

Patented Jan. 15, 1935 VARIABLE CAPACITY PUMP Frank P. Zierden, Cudahy, Wis.

Application October 12, 1932, Serial No. 637,508

(ci. 10s-16o) Claims.

This invention relates to a hydraulic transmission embodying a pump to which power is applied and by the action of which a noncom pressible fluid iscaused to actuate amotor which 5 is operatively connected to a part to be driven. The invention is illustrated in the accompanying drawings and consists, in certain novel features which will be hereinafter first fullydescribed and then particularly dened in the appended claims.

In the drawings, Fig. 1 is a vertical section through the motoi side of the apparatus taken at a. right angle to the axis of the same, Fig. 2 is a section on the line 2-2 of Fig. 1, the line 1 1 in Fig. 2 indicating the plane upon which the section shown in Fig. 1 is taken,

Fig. 3 is a section on the line 3-3 of Fig. 2,

Fig. 4 is a section corresponding to Fig. 3 but taken in a plane passing through the pistons and cylinders nearer the centerof the apparatus,

Fig. 5 is a section on the line 5-5 of Fig. 2,

Fig. 6 is a detail section of the relief valve.

In carrying out the invention, there is provided a casing comprising a preferably rectangular frame 1 having open sides and side plates or covers 2 which are secured upon the open sides of the frame and are coextensive therewith. At the centers of these covers or side plates are bosses 3 -concentric with openings through the side plates which receive a central through shaft 4. Hollow shafts 5 and 6 are fitted around the endportions of the central shaft 4 and packing, indicatedl at 7, is-provided around the hollow shafts at the bases thereof and compressed by glands 8 which are threaded into the respective bosses, as clearly shown. As best seen in Figure 2 of the drawings, similar packingl `boxes 9 are provided in the ends of the hollowshafts, around the central shaftfso that leakage of liquid is resisted in a highly etlicient manner. Arranged centrally within the casing is a partition 10 having a circular opening therethrough at its center and provided in its edges with slots 11, the purpose vof which will be hereinafter described. The partition divides the casing irrto a pump chamber and a motor chamber and the shafts 5 and 6 are formed with heads 12 andv 13,` respectively. The heads 12 and 13 constitute rotors and, as bestl seen in Figure 2, preferably loosely fit between the respective side plates 2 and the partition. 'Ihe rotor or head 12 is formed'with a boss 14 on its inner end and said boss fits about a bearing lug formed onl the inner end of the head 13 whereby the heads will be held in coaxial relation and willserve to mutually support each other and also to provide bearings for the central through shaft 4. It

should be noted that while frictional resistance to the rotation of the rotors will be minimized, leakage and waste of a non-compressible liquid utilized in the apparatus will belargely avoided due to the fact that the liquid under pressure 5 about the rotors will find its way into the clearance present between theA respective rotors, or heads, and the center partition and into passages 16. The liquid will be forced through the passages 16 to a small clearance which exists be- 10 tween the end of the bearing lug 15 and central surface of the boss 14 where the passages 16 ter-l minate. The liquid under pressure within the small clearance, above mentioned, will tend to push the heads or rotors 12 and 13 against the 15 respective end covers 2. thereby providing a liquid seal, and, as above stated, prevent the escape of the liquid. It will also be` noted that the boss 14 fits in the central opening in the partition 10 and the opposed surfaces will have a close running or sliding fit so that the moving parts 'may rotate freely with respect to each other within the central opening. The passages 16 extend through the head 12 from the circumference of the same toward the boss or hub 14 so that liquid may g5 pass to the opposed surfaces of the boss and the stud or lug 15 to lubricate the same and'facilltate the operation.

Each head has diametrical passages 17' formed therethrough and said passages are disposed at '30 right angles to each other and in diiferent vertical planes of the rotor. Slidably fitted in the passages 17 of the head or rotor 12 are rods 18 the length of which is greater tha'nthe diameter of the head so that the ends of the rods project beyond the circumference of the head, as w'ill be readily understood. The extremities of these rods are reduced. as shown at 19, and openings are formed through saidreducedextremities to receive shanks 20 which have their ends threaded, 40 as shown at 21. At one side of the rod, the shank 20 is expanded to form a piston 22 and at the opposite side a sleeve 23 isk threaded onto the shank and turned home against the end of the rod so that the shank will Abe firmly secured in place. The external diameter of the piston 22 and of the sleeve 23 is such that they will have a close running flt in cylinders 24 formed in a ring 25 which is mounted in a block l26 which is I, disposed within the casing between'the side plate oo and the partition and may be adjusted across the casing so as to control the direction 'and rate of flow of the operating liquid, as will presently more fully appear. It will be noted that the cylinders 24 are arranged in pairs with the members of 5l each pair axially alined and the pistons at the opposite ends of one rod 18 are disposed in the same plane so that in each head there are two piston rods each carrying pistons at both its ends and the rods and pistons carried thereby are arranged in parallel planes of the head. It should be understood that I do not limit myself to the number of piston rods carried by the head in either the pump or the motor and any desired number may be employed depending, of course, upon the character of work in which the device is to be employed.

The ring 25 is provided in its outer circumference with grooves 27 which are arranged midway the. sides of the ring and extend each part way around the circumference of the ring to be connected at its ends with the respective cylinders 24 through ports or passages 28, as shown. It will be understood that the diametrically opposite grooves are connected with the alined cylinders disposed in one plane so that each pair of cylinders will be connected with one of the grooves 27 and the alternate cylinders will communicate 'with the alternate grooves through passages which extend obliquely, in opposite directions from the ends of the respective cylinders to the central plane of the rotor head. The. block 26 is formed with a central opening in which the ring 25 nts with a close running ilt and in the circumferential surface of this opening, at opposite sides of the same, are grooves 29 which are longer than the grooves27 and are located in the plane of the latter grooves so that the alternate grooves 27 will communicate alternately with the respective grooves 29. In the side of the block 26 is an opening 30 leading outwardly from the respective groove 29 and in the frame 1 are recesses 31 which are of such length as to be always in communication with the respective opening 30 whether the block be set in a higher or lower position. The recesses 31 are provided in the pump side of the apparatus and an opening 32 leads from each recess 31 and constitutes the terminal of a passage formed in the side portion of the frame 1, the opposite end of said passage being at a recess 33 formed in the frame in the motor sideof the apparatus so that liquid forced from the pumping cylinders will be driven into the motor cylinders. The recesses 31 and 33 and passages or openings 32 are provided in the diametrically opposite sides of the frame so that when the apparatus is in operation there will be a continuous circulation of the liquid from the pump to the motor under pressure and from the motor to the pump without pressure.

of the apparatus so that it may be shifted vertically therein and on its upper sideat its center it is provided with an internally threaded socket 34, the upper end of whichis accommodated in an extension or boss 35 formed on the top of the casing. An adjusting screw 36 is swiveled in the top of the extension or boss 35 and is engaged in the socket 34, as shown clearly in Figs. 2 and 3, and the lupper extremity of this adjusting screw is provided with any convenient form of handle, indicated at 37, so that the screw may be rotated when desired. Rotation of thel screw will, of course, cause the socket or sleeve 34 to ride up or down on the screw and thereby set the block 26 in the desired position. It will be noted that the several shafts 4, 5 and 6.are xed in location while the block 26 may be raised or lowered and the ring 25 will, of. course, follow the movement of the block, the piston rods 18 being fmtrllted with longitudinal slots 38 through which the center through shaft 4 passes so that the presence of said shaft will not interfere with the desired adjustment of the working parts. Power for operating the apparatus is applied to the shaft 4 or the shaft 5. When power is applied to the shaft 5, the head 12 will, of course, rotate therewith and inasmuch as the pistons and piston rods will rotate with the head, the movement will be transmitted to the ring 25 but if the block 26 be adjusted so that the center of the ring 25 coincides with the axis of the head 12, the liquid contained in the several cylinders and passages will remain within the cylinders and will revolve with them for the reason that when the circumferential center of the ring 25 is coaxial with the axis of the head 12, the stroke of the respective pistons in the respective cylinders of the ring 25 is at zero and therefore cannot actuate the liquid in said cylinder. Consequently there will be no compression and therefore no motion transmitted to the motor.

The liquid in the chambers between the head 12 and 13 and the liquid above or below the block 26, depending upon the adjustment of the block, is not essential for the operation of the transmission, but merely increases its efficiency by serving as a lubricant forfthe several parts. The liquid in said chamber also provides means whereby leakage from the chamber can be largely eliminated` as it tends to provide a seal. The cubic capacity of the chambers wherein the heads 12 and 13 revolve remainsthe same, that is to say, the volume of liquid contained in said chambers is not affected during the course of revolution, or even by the changing of the pumping stroke which is, of course, effected by the raising or lowering of theblock 26. The slots 11 which are cut into the edges of the center partition 10, separating the chambers, will serve to connect the chambers and render them intercommunicating. Inasmuch as` the entire device is filled with liquid, the small amount of liquid which leaks past the pistons and past the circumferential surfaces of the cylinder rings in the pump and motor, due to the fact that the piston and cylinder rings must beiltted loosely enough to permit movement, will attempt to gain access to the chambers'. Obviously, if the chambers were filled with air this air could be compressed by the action of the piston and no effect would be had within the chambers. However, if the chambers are filled with oil, the liquid attempting to gain access to said chambers would be met with a very high resistance due to the fact that, as

above stated, the volume of liquid in the chamber does not change, and as oil'is non-compresslble, it does not become compressed. Therefore, the leakage of liquid from the high pressure passages past the pistons into the cylinders will cause static pressure to be raised within said chambers. It will be understood, that if there was no leakage of liquid from the high pressure passages, there would be no static pressure in the chambers. It will be further understood in this connection, that the liquid in the chambers is under pressure merely because the high pressure liquid leaks past the pistons into said chambers. The liquid under pressure will stop leakage into the low pressure passages. By providing the passages 11, the stabilization of the static pressure within the chambers is permitted. The passages also permit liquid to pass in or out of the chambers above or below the block 26. The passages 11', it is to be-noted, are the only passages been pointed out that leakage to the outside of the casing will be prevented by the end faces of the heads 12 and 13 being urged against the in- .ner facesof the end walls of the casing by the pressure of the liquid against the respective heads.

If, however, the block 26 be adjusted so` that its center and the center of the ring will be above or below the axis of the shaft and the head, the pistons will be caused to' make working strokes in the several cylinders so that liquid in the cylinders and the communicating passages at one side of the ring will be driven to the motor under pressure.

The motor is of the same construction as the pump, the head 13 carrying piston rods 39 which are slotted, as at 40, to accommodate the shaft 4 and carrying pistons 4l at their ends, the same in all respects as the pistons 22 or 23, working in corresponding cylinders 42. The head 13 is disposed within a ring 43 having the cylinders 42 formed therein and passages 44 lead from the ends of the respective cylinders vto grooves 45 in the circumference of the ring 43 corresponding to the grooves 27 in the pump. The grooves 45 in the ring 43 cooperate with grooves 46 in a block 47 and openings 48 lead from the grooves 46 to establish communication with the recesses 33, as will be understood upon reference to Fig.' 5. The ring 43 also has the clearance spaces 49 to accommodate the ends oi the respective piston rods and it will be noted that similar spaces 50 are provided in the ring 25 of the pump. The block 47 is of the same material as the block 26 but its dimensions are such that it is always eccentric tothe axes of the shafts 4, 5 and 6. It should be understood that the head 13 of the motor as well as the head 12 of the pump may be of any length and may carry any number of piston rods, the number vto be determined by the strength and size oi' the heads.

'An elbow or filling nozzle 51 is fitted in one side or end of the casing at the top of the same at such point as may be most convenient and this elbow or nozzle is equipped with a plug 52 whereby A it is normally closed. Oil or other non-compressible liquid is poured through this tllling nozzle or elbow into the casing and is intended to illl the interior of the casing around the rotors and between therotor heads and the respective rings. When the level of the liquid rises to the mouth of the elbow or nozzle, it will be known that the casing has been tllled and the closing plug 52 is then put in place. A pipe 53 is provided at each side of the casing Vand-has its lower end ntted in a valve casing 54 'from which a branch 55 extends into the casing to communicate with a passage 32, so as to establish the desired complete circulation. The valve casings 54 each contain a ball valve 56 which normally seats at the lower end of the casing, and leading from the lower end of the valve casing below the valve seat is a tube 57 which extends down into a reservoir 58 provided on the casing at the bottom of the same. At the upper end of each pipe 53 is a Tcoupling 59 from which a pipe 60 leads inwardly over the casing to a sleeve or tube 61 secured upon the top of the transmission casing. Rising from the bottom of this tube 61, within the tube, is apartition 62 having an opening 63 therethrough nearL its upper end and slidably fitting within the tube 6l, over said partition, is a head 64 having plungers 65 dependying therefrom at the opposite sides of the partition and ntting snugly between the partition and the respective side of the tube. An rexpansion spring 66 is disposed within the tube 61 and is through which establishes communication with a pressure gauge 69 of any approved construction. In filling the working parts of the apparatus with operating liquid, the plugs 70 in the upper ends of the couplings 59 are removed and the liquid is then poured through either pipe 53 as may be most convenient. The liquid supplied to the pipe 53 will, of course, pass at once to the bottom of the valve casing 54 and its flow from the casing will be prevented by the valve 56 resting in its seat so that the liquid will be forced to pass out through the branch 55 into the grooves and other passages of the motor. It is preferable that some pressure be applied to the liquid as it is poured into the apparatus so. that the motor will be caused to turn and act upon the incoming liquid to drive it into the pump and the several cylinders and passages therein. When the liquid has completed the circulation through all of the passages it will appear in the pipe 53 at the opposite side of the apparatus and the air which was in the apparatus will, oi course, escape through the latter pipe. When no more air bubbles appear and the level of the liquid rises to the coupling 59, it willbe known that the working passages and cylinders of the apparatus have been completely filled and the plugs 70 are then retted in place.

In the operation of the apparatus, the liquid will lower ends of the plungers willbe slightly above the lower sides of the passages through the pipes 60. Consequently, the liquid may pass under the plungers and the pressure on the plungers will act against the tension of the spring 66. Should the spring be overcome, the plungers and the head 64 will rise, as indicated in Figure 6, and the liquid may then pass through the opening y63 and find4 its way to the low pressure side of the apparatus. It should be understood that the relief valve will function in the same manner if the high pressure liquid should enter it through the opening at the opposite side, that is to say, through the low pressure side. 'Ihe liquid is drawn up from the outside Areservoir 58 through the low pr\essure valve 56 and from there into the low pressure working passages. 'I'he liquid is drawn up by a suction which is caused by the leakage from the ports and passages between the pump and the motor. By way of example, vwe may suppose that the'stroke of the pump was set to equal the stroke of the motor. rTheoretically, one rotation of the head of the pump .would force enough liquid into the motor to caus one rotation or complete turn oi the head in the motor, but the slight leakage of liquid from the passages will slightly diminish the ilow of liquid to the motor so that the complete rotation of the head of the motor will not take place, therefore, the motor is not capable of discharging the amount of liquid that was delivered into the pump for the reason that said motor is only capable of discharging the amount of liquid which is received from the pump; The liquid is therefore not returned to the pump in the same volume and a vacuum will occur in the low pres- Pump.

sure' passages between the pump and the motor.

`This vacuum will actuate the valve 56 for draw- 'resisting leakage, it may sometimes happen that leakage will-occur around some of the pistons or around the shafts and ilnd its way to the outside of the casing. This leaking liquid will be caught in the reservoirs 58 and when suction occurs through the apparatus, the valves 56 will be unseated and the liquid caught in the reservoirs 'will be drawn up through thetubes 57 and thence into the working passages so that the supply will be kept approximately constant.-

It is thought the operation will be readily understood from the foregoing description, taken in connection with the accompanying drawings. As has been stated, when the ring'25 is concentric: with the head 12, the working liquid will n be Put under compression. Should the block 26,- however, be shifted downwardly, for instance, as shown in Figs. 3 and 4, the ring \25 will have its center or axis shifted below the -center or axis of the shaft 4 'and the center of the rotor head 12. 'When the block andthe ring are lowered; the pistons 22 and 23 which are at the sides 'will be shifted to the upper 'ends "of the corresponding cylinders, 'as shownin Figllire 4. In this position of the parts, the grooves the sides of the ring lnre in communication with the grooves 29 inV the blockbut the grooves-27- on-the-'sides 'of 'the ring at the top The rotor alwaysmoves yclockwise and this movement will the pistons 22 and 23 to move relatively backward in their cylinders' owing to arrangement of the the back-k ward movement of the pistons serving to drive the liquid in the ends of the cylinders through fthe communicating vpassages 2B and the grooves 27 intothe grooves in the block. 'nie liquid at the left side ofthe apparatiwin Figs. 3 and 4 ivill, be put under compression and driven tothe motor side ofthe apparatus act upon in the head rotation of said head and the ring e head l2 rotates the liquid within and grooves will be compressed "previously explained, the liquid will be iforced from the pump into the motor for driving the motor and-will be discharged by said motor and returned to the pumpfor another cyclefit being understood..of course, as heretofore'eaplained, the leakage of liquid in the pasaageswill causea vacuum to be set up for drawingAiquidfrom the reservoir 58 back into the 'I'his rotation will he-imparted to the shaft 6 and said shaft may be connected with the parts or mechanism to be driven.

` 'Ihe apparatus is well adapted for use in auto'- mobiles and may be substituted for the usual' clutch and ton, it being noted that by simply adjusting the block 26, as before stated, the position of the ring will be changed relative to the head l2 so that vworking strokes will 'be made by the .pistons in the cylinders forforclength of the strokes of the pistons in' the cylinders and consequently the greater will be the pressure oi liquid from the pump to the motor. It is pointed out that if the ring k25 is lowered sq that its axis is below the of the shaft 4, the liquid in the cylinders will be forced through the passages in such a manner as to provide counter-clockwise rotation of the head.

The apparatusis simple and compact and may be very readily adjusted so that the driven member will be rotatedat any desired speed. When -applied to automobiles, it is desirable that, when a certain speed has been attained, the driven member be connected directly to the prime rnotor and for this purpose the" through shaft 4 is provided.

Having thus described the' invention, I claim:

l. In a hydraulic transmission, a casing having a chamber therein, a rotor in said chamber, a ring encircling said r'ot'or to rotate therewith, the ring being adjustable whereby it may be disposed concentric or eccentric tothe-rotor and its eccentricity may be varied, cylinders in said ring, piston rods slidably mounted diametrically through the rotor, andv pistons. carried' by the opposite ends of said rods transversely thereto and slidably iitting in' the cylinders.

2. In a hydraulic transmission, a casing hav ing a chamber therein, a block in the' chamber of the casing having an axial' opening therethrough, a ring rotatably iltted -in the opening of said block, av rotor within theopening in said ring, cooperating passages 4in wall of the casing and in the block to permit circulation of iluid therethrough, andcooperating passages formed in the ring and block to permit enculation of nuid therethrough, and means carried by the rotor and working in the ring 'to eil'ect pumping of fluid, the rotor Vhaving a varied eccentricity with respect to the cooperating-ring and block.

3. In a hydraulic transmiissiori,- a having a chamber therein, a block in said chamber having an opening therethrough, a ringrotatablytted in said opening, there being grooves in the block at diametrieally opposite points and diametrically opposite grooves inthe outer DG* riphery of the ring' to communicate withj the grooves intheblock, said ring carrying cylinders arranged -in pairs, the axes of the cylinders ofany pair being parallel and the cylinders cornmunicating at their outer ends with the adjacent grooves, a rotorodisposed inthe opening in the ring. piston slidably 'mounted diametricallir through the rotor, pistons carried by the OPPO- site ends of said rods and working in the respectively adjacent cylinders, and communicatingpassagesintheblockandthecasingtopermit circulation o'f the fluid.

v4. Inahydraulic-t 1w ac'asinghaving a chamber therein, a block in said chamber hav- ,ing an opening and provided with grooves at diametri'caly opmite points of said opening extending thereof, a ring rotatably nt'ted in the ,openingY of the block and having outer circumferential grooves adapted to communicate with the grooves inthe block, there being cylinders formed in the ring tangential to the inner circumference thereof and communic'ating at' their outer endsjwith the respective grooves, pistons working in-sthe cylinders, ,a

rotor-disposed within the ring. rods susablyacted through the rotorand connected wt their ends with the pistons at right angles to said rods, therods being reduced a't their extremities, means provided at the reduced extremities of the rod to secure the pistons, and passages in the casing communicating with the grooves in the block to establish a circulation of uid.

5. In ahydraulic transmission, a casing having a chamber therein, a block in said chamber having an opening therethrough and provided with circumferentially extending grooves vin ther wall of the opening, a ring rotatable in said opening and having' spaced circumferentialgrooves in its 'outer surface', the alternate grooves in the ring alternately registering with the grooves in the l block 'as the ring rotates, tangential cylinders in 

